[development] Any reason why having a javascript timer fire every 2.5 second for an ajax request to my own callback(listed below) that all it does is return the contents of 2 _session variables would take up so much resources?

[Greg Knaddison]

Drupal's bootstrap takes something like 50% of the total page
processing time on a typical page. You are still paying for that
overhead even though you don't need it.

See http://api.drupal.org/api/drupal/includes--bootstrap.inc/function/drupal_bootstrap/6
and look at something like the chatroom module's lightweight bootstrap
code:

http://drupalcode.org/viewvc/drupal/contributions/modules/chatroom/chatroomread.php?revision=1.29.4.19&view=markup

In particular:

require_once './includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_CONFIGURATION);
// Choose the minimum bootstrap level necessary for your module.

// Put your code here.
// See performance skyrocket.
// Rejoice.

Regards,
Greg

On Sun, Feb 6, 2011 at 10:15 AM, John Mitchell <mitchelljj98 at gmail.com> wrote:
> Any reason why having a javascript timer fire every 2.5 second for an ajax
> request to my own callback(listed below) that all it does is return the
> contents of 2 _session variables would take up so much resources?
>
> John
>
> function refreshcarttimer() {
>     print($_SESSION['num_items'] . ',' .  $_SESSION['uc_price']);
>     return;
> }
>
> /**
>  * Implementation of hook_menu().
>  */
>
> function product_type_menu() {
>   $items = array();
>
>   $items['cart/refreshcarttimer'] = array(
>     'title' => 'Refresh Shopping Cart',
>     'description' => 'Refresh Shopping Cart',
>     'page callback' => 'refreshcarttimer',
>     'access callback' => TRUE,
>     'type' => MENU_CALLBACK,
>   );
>   return $items;
> }
>
> On Sun, Feb 6, 2011 at 2:10 AM, John Mitchell <mitchelljj98 at gmail.com>
> wrote:
>>
>> I have a javascript timer set to fire every 2.5 seconds so that I can set
>> the current values for the items and total for the shopping cart summary.  I
>> would like to be able to get these values from client side cookies or
>> javascript global variables so that I don't have to make an ajax call to the
>> server but I have found that the DOM elements are not accessible within the
>> javascript function unless I run an ajax request to a page (listed below)
>> and after it returns then the DOM elements are accessible (i.e.
>> $(".num-items").html(numItems);) and now I can update them.  Having these
>> ajax requests run every 2.5 seconds for every client will not scale.
>>
>> How can I make Drupal DOM elements accessible within a javascript function
>> without having to do an ajax request to a page?
>>
>> Thanks,
>>
>> John
>>
>>     setInterval('updateShoppingCartInfo()', 2500);
>>
>>     function updateShoppingCartInfo(){
>>         var xmlHttpReq = new XMLHttpRequest();
>>         var url = 'https://' + document.domain + '/cart/refreshcarttimer';
>>         xmlHttpReq.open('post', url, true);
>>         xmlHttpReq.onreadystatechange = function() {
>>                if (xmlHttpReq.readyState != 4)  {
>>                    return;
>>                }
>>             else {
>>                 var responseText = xmlHttpReq.responseText;
>>                                 var numItems =
>> responseText.substr(0,responseText.indexOf(","));
>>                                 var ucPrice =
>> responseText.substr(responseText.indexOf(",")+1);
>>                                 $(".num-items").html(numItems);
>>                                 $(".uc-price").html(ucPrice);
>>             }
>>         }
>>         xmlHttpReq.send(null);
>>     }
>>
>>
>> --
>> John J. Mitchell
>
>
>
> --
> John J. Mitchell
>



-- 
Greg Knaddison | 720-310-5623 | http://growingventuresolutions.com
http://masteringdrupal.com - Videos and Tutorials